War in Heaven

The devil Screwtape explains to his nephew, Wormwood about the quarrel between God (the Enemy) and Satan (he refers to him as our Father):

What does He stand to make out of them? That is the insoluble question. I do not see that it can do any harm to tell you that this very problem was a chief cause of Our Father's quarrel with the Enemy. When the creation of man was first mooted and when, even at that stage, the Enemy freely confessed that He foresaw a certain episode about a cross, our Father very naturally sought an interview and asked for an explanation. The Enemy gave no reply except to produce the cock-and-bull story about disinterested love which He has been circulating ever since. This Our Father naturally could not accept. He implored the Enemy to lay His cards on the table, and gave Him every opportunity. He admitted that he felt a real anxiety to know the secret; the Enemy replied 'I wish with all my heart that you did.' It was, I imagine, at this stage in the interview that Our Father's disgust at such an unprovoked lack of confidence caused him to remove himself an infinite distance from the Presence with a suddenness which has given rise to the ridiculous Enemy story that he was forcibly thrown out of Heaven. Since then, we have begun to see why our Oppressor was so secretive. His throne depends on the secret. Members of His faction have frequently admitted that if ever we came to understand what He means by love, the war would be over and we should re-enter Heaven. And there lies the great task. We know that He cannot really love: nobody can: it doesn't make sense. If we could only find out what He is really up to!
~C.S. Lewis, The Screwtape Letters, (1942)